Using the Agent Builder Korn Shell-Based $hostnames Variable

For many applications, specifically network aware applications, the host name on which the application listens and services customer requests must be passed to the application on the command line. In many cases, the host name is a parameter you must specify for start, stop, and probe commands for the target resource type (on the Configure screen). However, the host name on which an application listens is cluster specific. The host name is determined when the resource is run on a cluster and cannot be determined when Agent Builder generates your resource type code.

To solve this problem, Agent Builder provides the $hostnames variable that you can specify on the command line for the start, stop, and probe commands.

The $hostnames variable is supported for use with Korn shell-based services only. The $hostnames variable is not supported for use with C-based and GDS-based services.

You specify the $hostnames variable exactly as you would an actual host name, for example:

% /opt/network_aware/echo_server -p port_no -l $hostnames

When a resource of the target resource type is run on a cluster, the LogicalHostname or SharedAddress host name that is configured for that resource (in the Network_resources_used resource property of the resource) is substituted for the value of the $hostnames variable.

If you configure the Network_resources_used property with multiple host names, the $hostnames variable contains all of them, each separated by a comma.